This invention relates to an apparatus for treating the surface of bulbous or tuberous crops, which apparatus comprises a substantially tubular treatment channel inclining upwards in the main direction of transport and comprising a top wall and a bottom wall, the bottom wall being made up of a number of drivable rollers arranged at slight mutual interspaces, parallel to each other and transversely to the main direction of transport and provided at their circumference with treatment means, such as brushes or profiles, and the top wall consisting of the lower part of a drivable endless conveyor belt traveling around return pulleys, while the top wall and the bottom wall are movable relative to each other to enable modification of the internal height of the treatment channel.
Such an apparatus is known from NL-C-166386 in applicant's name. There the rotary rollers take care of the transport of the products to be treated, while the conveyor belt is preferably driven opposite to the main direction of transport, which provides the possibility of optimum setting of the residence time of the products to be treated in the apparatus. In particular as a peel removing apparatus of steam-pretreated tuberous crops, this known apparatus has proved its utility over the years. The internal height of the treatment channel of the apparatus is adjusted to the products to be treated; a relatively great height for, for instance, kohlrabi and celeriac, and a relatively small height for, for instance, small potatoes and carrots. Here, in particular in the processing of relatively small products, problems can arise in that those products may not end up properly between the belt top wall and the roller bottom wall, resulting in jamming at the inlet of the treatment channel.